<!DOCTYPE html>
<html lang="zh-CN">
    <head>
        <meta charset="UTF-8" />
        <title>27_CSS3-新增边框-外边框轮廓</title>
        <style>
            div {
                width: 400px;
                height: 300px;
                background-color: aqua;
                border: 10px solid black;

                outline-width: 2px;
                outline-color: red;
                outline-style: none;
                outline-style: solid;
                outline-style: dashed;
                outline-style: dotted;
                outline-style: double;
                outline-style: groove;
                outline-style: ridge;
                outline-style: inset;
                outline-style: outset;

                /* outline-offset: 20px;
                outline-offset: -20px; */

                outline: 2px double green;

            }

            input {
                outline: none;
            }
        </style>
    </head>
    <body>
        <input type="text">

        <div>

        </div>
    </body>
</html>